Blockstream's Adam Back Pours $33M into European Bitcoin Treasury Firm

Adam Back, co-founder and CEO of Blockstream Corp., has made his largest public investment in Bitcoin treasury firm Capital B. He committed capital across multiple rounds to the Paris-listed company and now holds approximately 17.77% of its ordinary shares.

The €28.7 million ($33.1 million) private placement, which was completed on September 2, was subscribed entirely by Back. The funds were deployed to purchase 376 BTC for approximately €25.3 million ($29.2 million), bringing Capital B's total strategic holdings to 3,521 BTC.

Back has also accumulated warrants attached to tens of millions of shares through his multiple placements in Capital B since August 2025. If he exercises all the warrants from his latest placement at their respective strike prices, Capital B would receive approximately €49.4 million ($57 million) in additional capital without another public fundraising announcement.